Antibiotic Sensitivity Test

Question 1

Refers mostly to antibacterial agents that treats or prevents infectious diseases.

Answer 1

ANTIBIOTICS

Question 2

Chemotherapeutic agents/antimicrobials produced by molds or bacteria

Answer 2

ANTIBIOTICS

Question 3

isolated a strain of bacteria which lead to the development of erythromycin, a broad-spectrum antibiotic used to treat and prevent a wide range of infections.

Answer 3

aguilardo aguilar

Question 4

Inhibition of DNA-dependent

Answer 4

RNA polymerase
Rifampicin

Question 5

Cell membrane synthesis disruptors

Answer 5

Lipopeptides

Question 6

RNA synthesis inhibitors

Answer 6

Ansamycines

Question 7

Folate synthesis inhibitors

Answer 7

Sulfonamides

Question 8

Protein synthesis (305 and 50S inhibitors)

Answer 8

Tetracyclines
Aminoglycosides
Macrolides
Lincosamides
Amphenicols
Pleuromutilins
Oxazolidinones

Question 9

Method of evaluating the sensitivity or resistance of a pathogen to certain antibiotics.
Helps determine the type and/or dosage antimicrobials effective for treatment

Answer 9

ANTIBIOTIC SUSCEPTIBILITY TESTING

Question 10

a solid growth medium used in microbiology to test the susceptibility of bacteria to antibiotics

Answer 10

Mueller-Hinton Agar

Question 11

a chemical solution used to measure the number of bacteria in a liquid suspension

Answer 11

McFarland standard

Question 12

reaction behind McFarland standard

Answer 12

barium chloride + sulfuric acid = barrium sulfate

Question 13

white precipitate in McFarland standard

Answer 13

barrium sulfate

Question 14

METHODS OF SUSCEPTIBILITY TESTING

Usually performed in tubes or agar
Yields quantitative result
Determines minimum inhibitory concentration or minimum bactericidal concentration.

Answer 14

Dilution Method

Question 15

Dilution Method

Answer 15

Different Concentrations of Antibiotics
Incubate tubes at 37 C
16-18 h, observe which tubes are turbid
Spread Plate on Agar
Incubate tubes at 37 C
Observe for colonies

Question 16

METHODS OF SUSCEPTIBILITY TESTING
Usually performed in Mueller Hinton Agar (MHA) plates as it does not inhibits a class of antibiotics called sulfonamides
Usually yields qualitative results (sensitive, intermediate, resistant)
The diameter of the zone of inhibition is measured.
The size (usually in mm) is concurred with a standard chart to interpret if the bacteria is resistant, sensitive or intermediate.

Answer 16

Disc-Agar Diffusion Method

Question 17

Disc-Agar Diffusion Method Also known as

Answer 17

Also known as Kirby-Bauer Method

Question 18

MHA has no PABA w/c inhibits a class of antibiotics called

Answer 18

sulfonamides

Question 19

Disc-Agar Diffusion Method

Answer 19

pick 2-3 colonies
add to tube for mc farland standard
swab cotton in inoculum and to plate
antibiotic disks on plate using forceps
observe zone of inhibition

Question 20

METHODS OF SUSCEPTIBILITY TESTING
used for the minimum inhibitory concentration
small amounts of antimicrobial solutions to the wells of a microwell plate and Add a bacterial suspension to each well.

Answer 20

Microdilution

Question 21

METHODS OF SUSCEPTIBILITY TESTING

Quantitative test
Strip contains a gradient of antibiotic where MIC can be determined

Answer 21

E-test or Epsilometer test

Question 22

brand name based on “Ilo-ilo” crediting the drugs origin

Answer 22

Ilotycin and Ilosone

Question 23

genes that breakdown antibiotic, example penicillase

Answer 23

excretion channels

Question 24

a process where two or more species or individuals of the same species develop escalating adaptations and counter-adaptations against each other

Answer 24

evolutionary arms race

Question 25

competitively inhibits dihydropteroate synthase, the enzyme responsible for bacterial conversion of PABA to dihydrofolic acid

Answer 25

Sulfamethoxazole

Question 26

blocking the production of tetrahydrofolic acid (THF), the active form of folic acid, in susceptible organisms

Answer 26

Trimethoprim

Question 27

is a second generation fluoroquinolone that is active against many Gram negative and Gram positive bacteria. It produces its action through inhibition of bacterial DNA gyrase and topoisomerase IV

Answer 27

Ciprofloxacin

Question 28

Inhibits the synthesis of cell walls in gram-positive and gram-negative bacteria by binding to penicillin-binding proteins

Answer 28

Imipenem-EDTA

Question 29

nosocommial bacterial infection example mcrorg

Answer 29

Psuedomonas Aeruginosa

Question 30

any disease contracted by a patient while under medical care

Answer 30

nosocomial

Question 31

is known for its high level of antibiotic resistance, making it a challenging pathogen to treat. This resistance arises from multiple factors, including its low outer membrane permeability, which limits antibiotic entry, the presence of powerful efflux pumps that actively expel antibiotics, and antibiotic-inactivating enzymes that degrade the drugs before they can take effect.

Answer 31

Pseudomonas aeruginosa

Question 32

unidirectional transfer of genes between cells that are not direct descendants of one another, meaning bacteria can share genes with other bacteria, even with other species. This method of gene transfer allows cells to rapidly adapt and respond to their environment by acquiring new characteristics, which lets bacteria form antibiotic-resistant mechanisms that they can also transfer with others.

Answer 32

Horizontal gene transfer

Question 33

is specifically utilized for this experiment because it supports the growth of fastidious and nonfastidious organisms, the starch in the media absorbs toxins that may interfere with the antibiotic susceptibility test, and has no para-aminobenzoic acid (PABA). PABA is a vitamin-like substance synthesized by bacteria in their metabolic pathway which

Answer 33

Mueller Hinton Agar (MHA)

Question 34

is specifically used to spread the inoculum into the agar plate as it is able to absorb a greater amount of inoculum in one dip than an inoculating loop. This ability results in a more even distribution of bacteria on the plate to prepare a lawn culture for the experiment.

Answer 34

Cotton swab

Question 35

is particularly resistant to many antibiotics, especially those containing beta-lactams, due to its complex resistance mechanisms. Furthermore, this bacterium can form biofilms, which create a protective barrier, further enhancing its ability to withstand antibiotic treatments.

Answer 35

P. aeruginosa